JP7512907B2 - Underwater Equipment - Google Patents

Description

The present invention relates to underwater equipment.

Conventionally, as an underwater device used underwater, for example, as described in International Publication No. 2014/163141, a device that has a ballast tank and adjusts buoyancy by filling and discharging air into the ballast tank is known. This underwater device has a tank filled with compressed air, and when discharging the ballast tank, compressed air is supplied to the ballast tank to promote discharging the ballast tank.

International Publication No. 2014/163141

It is difficult to continue underwater activities with such underwater equipment. For example, compressed air is required when draining ballast tanks, and once the compressed air runs out, it must be replenished. This requires moving to land or receiving support from a support vessel to replenish the compressed air, which means that underwater activities must be interrupted.

Therefore, there is a need to develop underwater equipment that allows continuous underwater activities.

In accordance with one aspect of the present disclosure, the underwater device is an underwater device used underwater, and includes a ballast tank for adjusting buoyancy by filling and discharging air, a filling and discharging unit for filling and discharging air into the ballast tank, an air pressure measuring unit for measuring the air pressure in the ballast tank, a pipe for connecting the ballast tank to the outside and supplying air to the ballast tank, an on-off valve for switching the on-off state and off-off state of the pipe, and a control unit for controlling the refilling of air into the ballast tank. The control unit is configured to set the air pressure at the reference water level of the ballast tank to the reference air pressure, and when the air pressure in the ballast tank for filling and discharging air falls below a threshold value set to be equal to or lower than the reference air pressure, to cause the ballast tank to rise to the water surface, to operate the on-off valve to open the pipe, and to refill the ballast tank with air from the outside through the pipe. With this underwater device, air can be supplied to the ballast tank without using compressed air. Therefore, underwater activities can be continuously performed without refilling compressed air. In addition, a tank for storing compressed air is not required, and equipment for sending compressed air to the ballast tank is not required. This allows for the miniaturization of underwater equipment, and the space saved by installing compressed air tanks, etc. can be effectively used for other purposes.

In addition, in the underwater device according to one embodiment of the present disclosure, the reference air pressure may be atmospheric pressure. In this case, by connecting the inside of the ballast tank to the outside of the underwater device through piping, the air pressure at the reference water level in the ballast tank can be easily set to the reference air pressure.

In addition, in the underwater device according to one aspect of the present disclosure, the underwater device may be a water current power generation device that generates power using a water current.

The invention disclosed herein allows underwater equipment to continue underwater activities.

FIG. 1 is a diagram showing an overview of an underwater device according to an embodiment of the present disclosure. FIG. 2 is a diagram showing an outline of the electrical configuration of the underwater equipment of FIG. 1 . 4 is a flowchart showing the operation of the underwater equipment of FIG. 1 .

Embodiments of the present disclosure will be described below with reference to the drawings. Note that in the description of the drawings, the same elements are given the same reference numerals, and duplicate descriptions will be omitted.

Figure 1 is a diagram showing an overview of an underwater device according to an embodiment of the present disclosure. Figure 2 is a diagram showing a schematic of the electrical structure of the underwater device.

As shown in FIG. 1, the underwater device 1 is a device used underwater, and is applied to a water current power generation device that operates underwater. For example, the underwater device 1 floats a main body 11 underwater, rotates a turbine 12 provided on the main body 11 by the water current, and generates electricity by the rotation of the turbine 12. The underwater device 1 is installed, for example, in the ocean and generates electricity by ocean currents. The main body 11 is moored to an anchor 14 by a mooring rope 13. The anchor 14 is a heavy object installed on the seabed. A cable (not shown) is connected to the main body 11, and the generated electricity is transmitted through this cable. The underwater device 1 can float to the water surface and sink underwater by adjusting its buoyancy. Note that the underwater device 1 is a device used underwater, and does not include ships, moving objects, etc. that do not submerge but move only on the water surface.

As shown in FIG. 2, the underwater device 1 includes a ballast tank 2, an injection/drainage unit 3, an air pressure measuring unit 4, a liquid level measuring unit 5, piping 6, an on-off valve 7, and a control unit 8. The ballast tank 2 is provided inside the main body 11 of the underwater device 1. The ballast tank 2 is a tank that adjusts the buoyancy of the underwater device 1 by injecting and discharging water. For example, the ballast tank 2 injects seawater from outside the underwater device 1 to reduce its buoyancy, and discharges seawater from inside the tank to increase its buoyancy. The injection/drainage unit 3 is a unit that injects and drains water into and from the ballast tank 2. The injection/drainage unit 3 is provided midway through a pipe 31 that connects the ballast tank 2 to the outside of the underwater device 1. For example, the injection/drainage unit 3 has a pump, and the operation of the pump injects and drains water into and from the ballast tank 2 through the pipe 31. The injection/drainage unit 3 is electrically connected to the control unit 8 and operates according to a control signal from the control unit 8. For ease of explanation, FIG. 2 shows only one pipe as the pipe body 31, but the pipe body 31 may be made up of multiple pipes for water injection and drainage.

The air pressure measuring unit 4 is an air pressure measuring device that measures the air pressure inside the ballast tank 2. For example, an air pressure sensor capable of measuring air pressure is used as the air pressure measuring unit 4. Any type of air pressure sensor may be used as the air pressure measuring unit 4 as long as it can measure the air pressure inside the ballast tank 2. The air pressure measuring unit 4 is provided in the ballast tank 2 and measures the air pressure inside the ballast tank 2. The air pressure measuring unit 4 is electrically connected to the control unit 8 and outputs a measurement signal to the control unit 8.

The liquid level measuring unit 5 is a liquid level measuring device that measures the water level in the ballast tank 2. For example, a liquid level sensor capable of measuring the water level is used as the liquid level measuring unit 5. Any type of liquid level sensor may be used as the liquid level measuring unit 5 as long as it can measure the water level in the ballast tank 2. The liquid level measuring unit 5 is provided in the ballast tank 2 and measures the water level inside the ballast tank 2. The liquid level measuring unit 5 is electrically connected to the control unit 8 and outputs a measurement signal to the control unit 8.

The piping 6 is a tube that connects the ballast tank 2 to the outside of the underwater equipment 1 and supplies air to the ballast tank 2 from the outside. For example, one end of the piping 6 is connected to the top of the ballast tank 2, and the other end of the piping 6 is connected to the outside of the underwater equipment 1 at the top of the underwater equipment 1. Therefore, when the air pressure inside the ballast tank 2 is lower than atmospheric pressure, air can be taken into the ballast tank 2 through the piping 6.

The on-off valve 7 is provided in the piping 6 and is a valve that switches the piping 6 between an open state and a closed state. For example, a solenoid valve is used as the on-off valve 7, and it opens and closes in response to a control signal. When the on-off valve 7 is closed, the piping 6 is in a closed state, and outside air is not supplied to the ballast tank 2. On the other hand, when the on-off valve 7 is open, the piping 6 is in a connected state, and outside air is supplied to the ballast tank 2. The on-off valve 7 is electrically connected to the control unit 8, and opens and closes in response to a control signal from the control unit 8.

The control unit 8 is a controller or electronic control unit that controls the operation of the underwater equipment 1, and in particular controls the air supply to the ballast tank 2 in the underwater equipment 1. The control unit 8 also controls the buoyancy adjustment of the underwater equipment 1 and the filling and draining of the ballast tank 2. The control unit 8 is, for example, a computer composed of hardware such as a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory), and software such as programs stored in the ROM.

The control unit 8 reads and records the measurement signals of the various sensors. For example, the control unit 8 reads and records the measurement signals output from the air pressure measurement unit 4. The control unit 8 also reads and records the measurement signals output from the liquid level measurement unit 5. This recording process is repeated at a predetermined cycle. The control unit 8 performs a process of setting the reference air pressure. The reference air pressure is the reference air pressure in the ballast tank 2, and for example, the atmospheric pressure is set as the reference air pressure. Specifically, when the seawater in the ballast tank 2 is at the reference water level and the underwater equipment 1 is floating on the water surface, the control unit 8 opens the opening/closing valve 7 to communicate the inside of the ballast tank 2 with the outside air through the piping 6. As a result, the air pressure in the ballast tank 2 becomes atmospheric pressure, and the reference air pressure is set as atmospheric pressure. Here, the reference water level is, for example, the lowest water level in the ballast tank 2.

The control unit 8 sets the threshold air pressure. For example, the control unit 8 sets an air pressure value equal to or lower than the reference air pressure as the threshold air pressure. This threshold air pressure value is used to recognize that the air pressure in the ballast tank 2 has dropped. The control unit 8 performs filling and draining control. For example, the control unit 8 performs filling and draining control of the ballast tank 2 to adjust the buoyancy of the underwater device 1 in response to a command to sink and surface the underwater device 1. Specifically, the control unit 8 outputs a control signal to the filling and draining unit 3 to operate the filling and draining unit 3. When the underwater device 1 is to sink, the filling and draining unit 3 fills seawater into the ballast tank 2 through the pipe 31. On the other hand, when the underwater device 1 is to surface, the filling and draining unit 3 drains seawater from the ballast tank 2 through the pipe 31. At this time, the filling and draining unit 3 discharges seawater from the ballast tank 2 by power such as a pump without using compressed air.

The control unit 8 performs an air pressure determination process. The air pressure determination process is a process for determining whether or not the air pressure in the ballast tank 2 is below a threshold value. The control unit 8 determines whether or not the air pressure measured by the air pressure measurement unit 4 is below a threshold value. The control unit 8 performs a floating control of the underwater device 1. This floating control is a control for floating the underwater device 1 to the water surface when the ballast tank 2 needs to be replenished with air. For example, the control unit 8 discharges seawater from the ballast tank 2 to increase the buoyancy of the underwater device 1, causing the underwater device 1 to float. The control unit 8 performs an air replenishment process. This replenishment process is a process for replenishing air into the ballast tank 2. For example, the control unit 8 opens the opening/closing valve 7 when the underwater device 1 has floated to the water surface. This allows the inside of the ballast tank 2 to communicate with the outside air, and air is supplied into the ballast tank 2 through the piping 6.

The control unit 8 executes each process and control by, for example, introducing a program that causes the above-mentioned air pressure setting process, filling and draining control, air pressure determination process, floating control, and air refilling process to function. The control unit 8 may also be configured with individual control units that execute each process or control. For example, the control unit 8 may be configured to have individual control units, such as an air pressure setting unit, a filling and draining control unit, an air pressure determination unit, a floating control unit, and an air refilling unit.

Next, the operation of the underwater device 1 according to this embodiment will be described.

Figure 3 is a flowchart showing the air replenishment control of the underwater device 1. The flowchart in Figure 3 is executed by the control unit 8, for example, when the underwater device 1 is in operation. First, as shown in step S10 (hereinafter simply referred to as "S10", and the same applies to the subsequent steps), a reference air pressure setting process is performed. This setting process is a process for setting the reference air pressure when the seawater in the ballast tank 2 is at the reference water level. For example, when the seawater in the ballast tank 2 is at the reference water level (e.g., the lowest water level) and the underwater device 1 is floating on the water surface, the control unit 8 opens the opening/closing valve 7 to communicate the inside of the ballast tank 2 with the outside air through the piping 6. As a result, the air pressure in the ballast tank 2 becomes atmospheric pressure, and the reference air pressure is set as atmospheric pressure.

Then, the control process proceeds to S12, where the filling and draining control is performed. The filling and draining control is a control for filling and draining the ballast tank 2 in order to sink or surface the underwater device 1. For example, when sinking the underwater device 1, the control unit 8 outputs a control signal to the filling and draining unit 3 to operate the filling and draining unit 3 and inject seawater into the ballast tank 2 through the pipe body 31. On the other hand, when surfacing the underwater device 1, the control unit 8 outputs a control signal to the filling and draining unit 3 to operate the filling and draining unit 3 and discharge seawater from the ballast tank 2 through the pipe body 31.

By filling and discharging the ballast tank 2 in this way, the air in the ballast tank 2 dissolves into seawater, which is then discharged. This reduces the amount of air in the ballast tank 2, causing the air pressure in the ballast tank 2 to gradually decrease and fall below the reference air pressure.

Then, the control process proceeds to S14, where the control unit 8 determines whether the air pressure inside the ballast tank 2 is below the threshold value. That is, the control unit 8 determines whether the air pressure measured by the air pressure measurement unit 4 is below a predetermined threshold value. In this way, by determining whether the air pressure inside the ballast tank 2 is below the threshold value, it is possible to determine whether it is time to refill the ballast tank 2 with air.

If it is determined in S14 that the air pressure in the ballast tank 2 is not below the threshold, the control process proceeds to S20. On the other hand, if it is determined in S14 that the air pressure in the ballast tank 2 is below the threshold, surfacing control is performed (S16). The surfacing control is a control for causing the underwater device 1 to float to the water surface in order to replenish air into the ballast tank 2. For example, the control unit 8 outputs a control signal to the filling and discharging unit 3 to operate the filling and discharging unit 3 and discharge seawater from the ballast tank 2. This increases the buoyancy of the underwater device 1, causing the underwater device 1 to float toward the water surface.

Then, when the underwater device 1 rises to the water surface, air refilling processing is performed (S18). The air refilling processing is a processing for introducing outside air into the ballast tank 2 to refill air. For example, the control unit 8 outputs a control signal to the on-off valve 7 to open the on-off valve 7 and put the piping 6 into a communication state. As a result, the inside of the ballast tank 2 communicates with the outside air, and air is supplied into the ballast tank 2 through the piping 6. At this time, since the air pressure in the ballast tank 2 is lower than the atmospheric pressure, air can be easily refilled into the ballast tank 2 simply by opening the on-off valve 7. At this time, the water level of the ballast tank 2 is set to, for example, the reference water level. In this way, by refilling the ballast tank 2 with air using outside air, it is not necessary to carry compressed air in the underwater device 1. Therefore, the underwater device can be made smaller in size. In addition, since no space is required for installing a compressed air tank or the like, the internal space of the underwater device 1 can be effectively used for other purposes.

Then, the control process proceeds to S20, where it is determined whether or not the operation of the underwater device 1 is to be completed. Completing the operation of the underwater device 1 means stopping the operation of the underwater device 1, for example, when performing maintenance on the underwater device 1 or when removing the underwater device 1. Not completing the operation of the underwater device 1 means continuing to operate the underwater device 1. If it is determined in S20 that the operation of the underwater device 1 is not to be completed, the control process returns to S12, and filling and draining control is executed. On the other hand, if it is determined in S20 that the operation of the underwater device 1 is to be completed, the series of control processes in FIG. 3 is terminated.

As described above, the underwater equipment 1 according to this embodiment can supply air to the ballast tank 2 without using compressed air. Therefore, underwater activities can be continued without refilling compressed air. In other words, there is no need to stop operation and refill compressed air when the compressed air runs out. Therefore, underwater activities of the underwater equipment 1 can be carried out efficiently.

In addition, with the underwater device 1 according to this embodiment, a tank for storing compressed air is not required, and no equipment for sending compressed air to the ballast tank 2 is required. This allows the underwater device 1 to be made smaller, and the space for installing a compressed air tank, etc. can be effectively used for other purposes.

In addition, in the underwater device 1 according to this embodiment, when the reference air pressure is atmospheric pressure, the air pressure at the reference water level in the ballast tank 2 can be easily set to the reference air pressure by connecting the inside of the ballast tank 2 to the outside of the underwater device 1 through the piping 6.

In this way, this disclosure can contribute, for example, to Goal 14 of the United Nations-led Sustainable Development Goals (SDGs): "Conserve and sustainably use the oceans, seas and marine resources for sustainable development."

Although the embodiments of the present disclosure have been described above, the present invention is not limited to the above-described embodiments. The present invention can be implemented in various modified forms without departing from the spirit of the claims.

For example, in the above embodiment, the underwater device 1 is installed in the sea to generate power, but it may be installed underwater, such as in a river, to generate power. Even in this case, the same effects as those of the above embodiment can be obtained.

In addition, in the above-mentioned embodiment, the underwater device 1 is applied to a water current power generation device, but the underwater device 1 may be applied to devices other than a water current power generation device. For example, the underwater device 1 may be applied to a submersible research vessel, an underwater exploration vessel, a submarine, etc. Even in this case, the same effects as those of the above-mentioned embodiment can be obtained.

Reference Signs List 1 Underwater equipment 2 Ballast tank 3 Injection/discharge section 4 Pressure measurement section 5 Liquid level measurement section 6 Pipe 7 Opening/closing valve 8 Control section 11 Main body 12 Turbine 13 Mooring rope 14 Anchor 31 Pipe body

Claims (4)

In underwater equipment used underwater,
A ballast tank that adjusts buoyancy by filling and discharging water;
An inlet/outlet unit for injecting and discharging the ballast tank;
An air pressure measuring unit that measures the air pressure in the ballast tank;
A pipe for connecting the ballast tank to the outside and supplying air to the ballast tank;
an on-off valve provided in the pipe for switching between a communication state and a cut-off state of the pipe;
A control unit that controls the replenishment of air into the ballast tank,
The control unit is
performing a floating control for floating the underwater device to the water surface in order to replenish the ballast tank with air;
The air pressure at the reference water level of the ballast tank is set to a reference air pressure, and when the air pressure in the ballast tank where the filling and discharging is performed falls below a threshold value set to be equal to or lower than the reference air pressure , the floating control is used to float the entire underwater equipment to the water surface, and the opening/closing valve is operated to open the piping, and air is replenished into the ballast tank from the outside through the piping.
Underwater equipment. The underwater device according to claim 1 , wherein the control unit performs the floating control by discharging water from the ballast tank to increase the buoyancy of the underwater device, thereby floating the underwater device to the water surface. 3. The underwater device according to claim 1 , wherein the reference pressure is atmospheric pressure. The underwater device according to claim 1 , wherein the underwater device is a water current power generation device that generates power using a water current.

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